Process for recovery of hydrocarbon oil from shale



April 24, 1951 w. l. THOMPSON PROCESS FOR RECOVERY OF' HYDROCARBON OILFROM SHALE Filed Aug. lO, 1944 ru, we nm eo vb n au U n O s P m O m .L miu. .Hb m

Patented pr. 24, 1951 PROCESS ros RECOVERY QF HYQBQ- 95333951 9.1L FROM'llt? William I. Thompson, Elizabeth, N. J., assgnor toStandard .OilDevelopment Company, a. coriporation of Delaware Appneaiqn Aggtst io,1944, serial No. 514,8,584 2 claims. (o1. 2oz- 14) The object of thepresent invention is to providlea cess and suitable apparatus thereforfor recovering hydrocarbon oil"f`rom tar sands aid/ r'shalelf"""Prior'te my invention others had proposed methods for recoveringhydrocarbon oils from tarfsands and shales. Usually the prior methodsYinvlved4 heating of the oil-,containing material 'to'convertthehydrocarbon oilorming material 'into' volatile constituents and a fixedcarbon. These o'peratioris were performed in a retort in which ytheshale or tar sand Was'treated in a processessentially intermittent.According to my presen-t invention, I provide a process" and I'suitableapparatus therefor whereby tar sands and/or shales from whichhydrocarbon cils are to be recovered, are heated in powdered form, or atleast in divided form, to a temperature ysufficiently high to ca usecoking of"`tlie' "hydrocarbon oil-forming constituents tial ingresenthat the hyeroear'bon oir-1S eent'e'rted'to a velatile product and ataror ceke. llv'ola'tile hydrocarbons are then treated ac'- co ing -to thecustomary oil renery vpractice a-iidseparated into various'fractions',suc-h as normally gaseous hydrocarbons, gasoline 'consti-'tuenta 'gasoil, tar, coke, and the like, as desirefd. 'lih'e fixed vcarbon or cokewhich is left oir-the sander spent shalei is burnt to supply heat`f'orlthe process.`

The .present application describes in detail an arrangement of'apparatus elements for using theheating value of the coke to carry outthe 'cokingreaction In general, the method'com'- prises van applicationof the so-called fluidsolid's`ltech nique 'to this problem. Byfluidsollids technique, I mean an operation in Which the sol-idymaterial undergoing treatment is maintained il'n la dense suspension ina delayed settling Zone'by eontrolling'the velocity of a gasifornmaterial Yflcjvving therethrough at a t'suilciently ldtv'value that thesolid material forms a dense, turbulent, mo'bile mass of solid in gasresembling a'boiling" liquid', all of Which will morefiilly yaridatlarge appear hereinafter. i A"In the accompanying drawing, `I lfiaveshown diagrammatically a suitable apparatus` in vv ich l red mediterenef my .inveiition maybe ,d into' praqiealeffet. f Benning 4in A,defalilt0 the drawing, .a liar .Send er Va'slialle ,the @latter Ainsubdividediorrn having ieleslze of, say,V 100 mesh up to 1A; linchfinroducedinto the present'ksysteni i .and thfenfedischargsdietd.aies@which it is' withdrawn into' a screw lll conveyor 3, which may "be ofthe compression sere'w'type. The feeder charges the sand or't'a'r inaline 4 where itinixesv with hot, burnt and spent shale or tar sand fromline 5 and Subsc-"- quently with a liquid product of the coking which ischarged into line 4 from line 6, the sourceoi this liquid material inline 6' being more 'fully identiiied hereinafter. At this point `I willsimply point out that it is a hydrocarbon in liquid form produced as aresult'of coking'." The mix# ture of spent shale or tar sand 'andhydrocarbon, the' latterbeing essentially vaporized 'by the hot spentshaleortar `sand,`formsa suspersic-n in iine d, which suspension iscarried'into the bottom of coking drum l0 which, as Vcan be seen, isessentially a cylindrical shell or case havl ing conical upper and lowersections. In the colring zone l@ the linear velocity of the gasiformhiaterial is controlled within the limits of'irom 1A to l0 it. persecond, depending upon the paiticle size of thesolids therein contained.If, for instance, the solids have a particle size of around 200 mesh,the Vgas velocity inthe vessel I0 is 'froin 11/2 to 3ft. per second,which will cause the fo'rmation of the dense, turbulent, fluidized masswhich I have previously referred'to. Actually another .way of describingthe reaction Vessell is to say that it is a delayed settler Whereinthevelocity of the gas is insulicient to carry the main bull; of theproductoverhead and out of the reactorbut SuCient, nevertheless, to support aibody of the solid in the reaction Zone to forinthe densephasesuspensionfof course, Iif the' yparticle size is' 1A; inch orlarger on the average'ih diameter, the gas velocity must b'sorne wliathigher, say u'p-"to l0 vto'12 ftf'per L secon'd. In the' case Where theshale or tar sand 4is in the form of relatively large aggregatesth'eheat which it is confronted inte'iaetieri zone sery's te ydecompose theagglutinants contained the ramps Qfshale, andthe like and .fo clause thShale ,and thelist: te disintegrate" physically.

A temperature of 900 F. t'o'1000"7 F., approggimately, is maintainedWithin the reactionl Zone i6- The presser? .is 'notgeiiieal and ,may1b.@ tf rnespheric ohr e' 4few pounds above atmospheric, in @ther werds,-Sueient i0 Overcome re's drops in the system. The shale or .saneremains resident in the reaction zone for a `sufcientpe riod ottime tor,efiectthe desired conversion'. `yIn the oase of tar sand, thisresidence'timeis from 1 to 3 minutes. The resultffof the cokijngorhe'atingoperation in`.,.the.vess,el l0 is to convert lhigh molecularWeight constituents of ,the'shale'jor sand into volatile hydrocarbonswhich are withdrawn through line l2 and into a spent material which iswithdrawn through a draw-olf pipe 90.

Referring again to the interior of the reaction zone I0, I provide aforaminous member G, which may be a screen or grid, to aid in thedistribution of the gasiform material in the reaction zone, and underthe ow conditions which I have named .there will be an upper dense phaselevel, which I have indicated at L which is xed by fixing the amount ofpowdered shale or sand which is maintained in the reaction zone and bythe velocity of the gas. Essentially, when the velocity of the gas issufficiently low to maintain the dense phase suspension previouslyreferred to, the height of the level L is controlled by the rate atwhich solid material is withdrawn. A controlled amount of material isWithdrawn through lll and is discharged into a pipe I5 where it mixeswith air or other oxygen-containing gas, as will subsequently appear. Itshould be pointed out, however, that in order to cause good ilowabilityin line I4, the same should be provided with a number of taps (notshown) into which a slow current of gasiform material, such as flue gas,steam, normally gaseous hydrocarbons, and the like, are forced toprevent bridging and/or plugging of draw-off pipe le. rIhe shale or tarsand, as stated, is discharged into air stream l Where it forms asuspension which is then conveyed into the bottom of a combustion zone20. This combustion zone is similar in shape and construction to cokingzone lli, that is to say, it consists of a cylindrical case or shellhaving conical upper and lower sections and is also provided with adistribution screen or grid G. Here also the velocity of the air and theamount of shale maintained in the combustion Zone 20 is adjusted so asto form a dense phase upper suspension at L, in which suspension thefixed carbon on the sand or shale is consumed by combustion thus causingheating of the spent shale to a temperature of l000 Ii'. to 1175" F.,whereupon the spent shale is Withdrawn through pipe 5 and mixed with thefresh shale or tar sand and recycled to coking drum l0, the hot shaleproviding the heat necessary to support the pyrolitic action takingplace in coking or distilling vessel I0.

The amount of spent shale circulated to the combustion Zone by line I6and admixed with the cold fresh shale or tar sand in line f should besufficient to raise the temperature of the mixture to the reactortemperature and to supply heat for the cracking reaction. This wouldrequire in the order of from 5 to 10 parts by weight of hot spent shaleor tar sand per part of cold fresh shale or sand. It is also pointed outthat draw-01T pipe 5 is provided with a flow control valve l' whichcontrols, of course, the amount of spent shale Withdrawn through line 5and is also provided with a plurality of taps into which a gas, such asair or ue gas, may be continuously fed to prevent bridging or pluggingof draw-off pipe 5.

Referring back again to distillation and/or coking zone l0, the gasiformmaterial above the level L becomes or is greatly depleted in solidcontent since the main body of the solids remains in the suspensionbelow L. Thus by controlling the amount of solid and the velocity inlil, as previously indicated, the upper dense phase level will be at Land will have a weight of -25 lbs. per cubic foot. Above L theconcentration of solid in the gas may be lowered to the extent that itweighs only about 0.025 to 0.030 lb. per

cubic foot. This dilute suspension passes through a number of cycloneswhich I have indicated at C disposed in the upper conical section of i0,which cyclones cause the separation of the solid from the gas bycentrifugal action and the return by gravity of the separated solid tothe main body between G and L, While the gasiform material is Withdrawnoverhead through line 30 containing only minor amounts of entrainedsolid. It is at a temperature of around 900 F., to 975 F. and it passesinto a knockdown drum or cooler 3l where it is partially cooled, say toa temperature of 650 F. for the purpose of condensing out the heavieroils, which oils will contain the unseparated lines. This slurry iswithdrawn from the bottom and thence is forced by pump 33 into line 5for recycling to I0, as previously indicated.

Overhead from knockdown drum 3l, I withdraw through line 35 ahydrocarbon fraction in gasiform state which is then discharged into aheat exchanger 40 in which further cooling and condensation takes place.The product from this exchanger, which is part liquid and part vapor, iswithdrawn through line 42 and discharged into a Water quench zone 45from which I withdraw normally gaseous hydrocarbons overhead throughline 46, while the quenched material is withdrawn through line lll. Thequenching water is introduced through line 50. The quenched material isthen pumped by pump 48 into a separator 5l from which the hydrocarbonoil may be Withdrawn through line 52 while the water is withdrawnthrough line 53.

Referring to the material in line 6, a portion thereof may be bypassedthrough line 6I into a heat exchanger 62 in which it is cooled to atemperature of 300 F. to 500 F. and thence discharged via line 63 intoknockdown drum 3l.

Heat exchangers il'and 62 are cooled by means or-water from drum 64introduced through lines 65 and 66, respectively. Steam generated inheat exchangers @0 and 62 at about 125 lbs. per square inch is returnedto drum 6d through lines 61 and 68, respectively, and withdrawn from thedrum through line 69.

Referring again to combustion zone 20, above L there is a second densephase suspension which I have designated as S2. This is formed byinterposing a second foraminous member G2 at a point spaced above L andhere also by controlling velocity and the amount of solid there is asecond dense phase suspension and an upper level at L2. In other words,in combustion zone 20 I have two separated dense phase suspensions.Interposed, as will be noted, in the second and/or upper dense phasesuspension is a coil 10 containing water, which water is converted intosteam by heat interchange with the hot spent shale, which steam isdischarged into vessel l2 and withdrawn through line 13, the water beingfed to the coil through line lll. Thus I have provided means for forminga quantity of steam which may be used in my present process. Above L2the concentration of solid in the gas, Which in this case isregeneration vapors, is greatly depleted so that whereas the suspensionWeighs from 15-25 lbs. per cubic foot in both dense phase suspensions,in the space above Lz' it may be of the order of a density of from 0.025to 0.030 lb. per cubic foot, and this dilute suspension is then forcedthrough one or more centrifugal separators C' disposed in the upperportion of 22 Where thesuspension in passing through is separated fromentrained solids which are returned to the upper dense phase suspension,while the regeneration fumes are withdrawn through line 88, thencepassed through a gas turbine 8| before they are vented from the systemthrough line 82 thus providing a portion of the power required tooperate air compressor 84 which pumps air to the preheating zone 92through line 99, as described above, and to combustion zone 20, and tostorage zone |52, described below. The turbine'l may be operated on thesame shaft as steam turbine 83 which operates compressor 84.

Referring again to distillation and/or coking zone l0, the spent shaleto be rejected from the system is withdrawn through a line 90 anddischarged into a preheater 92 where it contacts in the form of a densesuspension, the air entering said preheater through line 94. The aircontacts the hot shale and is preheated thereby and is withdrawn throughline |90, and it is this preheated air which eventually mixes with thespent shale withdrawn from distillation zone I8 through line |11 to formthe suspension which is conducted to combustion zone 2i), as previouslydescribed.

In preheating zone 92, the velocity of the air is fixed within thelimits of from 1/2 to 10 ft. per second, preferably 11/2 to 3 ft. persecond, so as to form the dense phase suspension having` an upper levelat L. Here also I provide a screen G which serves to aid in thedistribution of the air. In order to provide a further quantity of steamfor use in the process or for some other useful purpose, I may interposea water coil I5 in the mass of dense suspension, in which water ispreheated or converted to steam. The spent shale is withdrawn frompreheater 92 through line |30, mixed with air from line |3| andconducted into the top of a storage Vessel |52, thence withdrawn throughline |60 and discharged into a car or other conveyance |62 andwithdrawnfrom the system. Here also, in order to recover heat for some usefulpurpose, I dispose within the storage zone |52 a water coil |70 in whichboiler feed water may be preheated.

Thus I have described an operation for converting shale or tar sandsinto hydrocarbon oils which may be subsequently processed to producegasoline, gas oil, heating oil, and the like.

My present invention involves essentially the following novel features:

1. Utilization of the fluid-solid technique to treat the raw materialcontinuously and eiliciently in an economical manner.

2. To make the system substantially self-supporting regarding heatrequirements by burning the fixed carbon on the spent shale or tarsands.

3. Economizing in utilities by utilizing the energy of regenerationfumes and hot spent shale for operating waste heat boilers and turbines.

My process is suited for recovering valuable hydrocarbon oils fromnatural deposits known as Athabaska sands, oil shales, and the like.

Many modications of my invention will be apparent to those skilled inthe art without departing from the spirit thereof.

What I claim is:

1. In the continuous process of recovering hydrocarbon oil fromoil-bearing minerals by distilling said minerals in a luidized bed ofsolids maintained in a distillation zone, withdrawing spent solidresidue, burning withdrawn residue with a combustion-supporting gas in ailuidized bed maintained in a combustion zone, and returning heatedresidue from said combustion zone to said distillation zone to supplyheat to the latter, the improvement which comprises preheating saidcombustion-supporting gas in direct y contact with hot fluidized soliddistillation residue withdrawn from said distillation zone, carrying outsaid burning in two separate superimposed fluid beds within saidcombustion zone, vaporizing a liquid by heat exchange with the upper oneof said superimposed beds, transferring substantially all the heatgenerated in the lower one of said superimposed beds to the materialsforming said lower superimposed bed, withdrawing all of said returningheated residue from` said lower superimposed bed, cooling the volatileeiuent of said distillation zone just suiiiciently to condense a heavyoil fraction, mixing said returning heated residue with said mineralsand said condensed oil fraction outside said Zones to Vaporize said oilfraction and to form a dilute solids-in-gas suspension, and passing thesuspension so formed to said distillation zone.

2. The method of yclaim 1 in which hot fumes are Withdrawn from thecombustion zone and passed through a system adapted to recover at leasta portion of their energy content as kinetic energy. A

WILLIAM I. THOMPSON.

REFERENCES CITED The following references are of record in the Ile lofthis patent:

UNITED STATES PATENTS Number Y' Name Date 1,432,101 Danchwardt Oct. 17,1922 1,458,983 Kirby June 19, 1923 1,669,023 Runge May 8, 1928 1,704,956Trumble Mar. 12, 1929 1,824,282 Loughrey Sept. 22, 1931 1,899,887 ThieleFeb. 28, 1933 1,950,558 Karrick Mar. 13, 1934 1,958,918 Karrick May 15,1934 1,983,943 Odell Dec. 11, 1934 2,367,281 Johnson Jan. 16, 19452,406,810 Day Sept. 3, 1946 2,480,670 Peck Aug. 30, 1949 FOREIGN PATENTSNumber Country Date 189,542 Great Britain Dec. 1, 1922

1. IN THE CONTINUOUS PROCESS OF RECOVERING HYDROCARBON OIL FROM OIL-BEARING MINERALS BY DISTILLING SAID MINERALS IN A FLUIDIZED BED OF SOLIDS MAINTAINED IN A DISTILLATION ZONE, WITHDRAWING SPENT SOLID RESIDUE, BURNING WITHDRAWN RESIDUE WITH A COMBUSTION-SUPPORTING GAS IN A FLUIDIZED BED MAINTAINED IN A COMBUSTION ZONE, AND RETURNING HEATED RESIDUE FROM SAID COMBUSTION ZONE TO SAID DISTILLATION ZONE TO SUPPLY HEAT TO THE LATTER, THE IMPROVEMENT WHICH COMPRISES PREHEATING SAID COMBUSTION-SUPPORTING GAS IN DIRECT CONTACT WITH HOT FLUIDIZED SOLID DISTILLATION RESIDUE WITHDRAWN FROM SAID DISTILLATION ZONE, CARRYING OUT SAID BURNING IN TWO SEPARATE SUPERIMPOSED FLUID BEDS WITHIN SAID COMBUSTION ZONE, CARRYING A LIQUID BY HEAT EXCHANGE WITH THE UPPER ONE OF SAID SUPERIMPOSED BED, WITHDRAWING ALL OF TIALLY ALL THE HEAT GENERATED IN THE LOWER ONE OF SAID SUPERIMPOSED BEDS TO THE MATERIALS FORMING SAID LOWER SUPERIMPOSED BED, WITHDRAWING ALL OF SAID RETURNING HEATED RESIDUE FROM SAID LOWER SUPERIMPOSED BED, COOLING THE VOLATILE EFFLUENT OF SAID DISTILLATION ZONE JUST SUFFICIENT TO CONDENSE A HEAVY OIL FRACTION, MIXING AND RETURNING HEATED RESIDUE WITH SAID MINERALS AND SAID CONDENSED OIL FRACTION OUTSIDE SAID ZONES TO VAPORIZE SAID OIL FRACTION AND TO FORM A DILUTE SOLIDS-IN-GAS SUSPENSION, AND PASSING THE SUSPENSION SO FORMED TO SAID DISTILLATION ZONE. 